code: def get_duration(json_line):
      dur = json_line["duration"]
      if dur is None:
          wav_path = json_line["audio_filepath"]
          json_line["duration"] = sox.file_info.duration(wav_path)
      return json_line
  
file_path: NeMo/scripts/speaker_tasks/filelist_to_manifest.py
imports: import argparse
  import json
  import os
  import random
  import librosa
  import numpy
  import soundfile
  import sox
  from sklearn.model_selection import StratifiedShuffleSplit
  from tqdm.contrib.concurrent import process_map
  from nemo.collections.asr.parts.utils.manifest_utils import read_manifest
label_desc: Use image node_id 5 for calling a global function with example usage: get_duration(json_line) and returns: json_line